Ablation devices have been used to remove tissue within patients in a variety of medical procedures. When in use, ablation devices are often operated throughout a range of power settings. Higher power settings are often used to remove tissue via vaporization and lower settings are used for desiccation. Some ablation devices include aspiration systems to remove fluid or particulates, or both, from a surgery site within a patient. Conventional aspiration systems remove fluid and particulates from a surgery site at the same aspiration rate regardless of the power setting of the active electrode. An aspiration rate large enough to properly remove material generated at a high power setting for an active electrode is too large of an aspiration rate for a low power setting for the active electrode. In particular, the aspiration rate corresponding with the high power setting interferes with a plasma field or ionized gas vapor layer at the active electrode generated at a low power setting such as by pulling the plasma field away from the active electrode, thus affecting the behavior of the plasma field.